It is well known to restrain an occupant in a seat by a shoulder belt extending diagonally across the upper torso between an inboard anchorage generally adjacent the hip of the occupant and an outboard anchorage on the roof rail or pillar of the vehicle body generally adjacent and behind the shoulder of the seat occupant. U.S. Pat. No. 3,680,883, issued to Keppel et al on Aug. 1, 1972 provides a track extending longitudinally along the roof rail and mounting a belt carriage which slidably receives the belt. The belt carriage is movable forwardly along the track to stow the diagonal shoulder belt forwardly of the occupant seat to facilitate occupant ingress and egress and rearwardly along the track to establish the shoulder belt in its normal occupant restraining position. The carriage of Keppel is conventionally moved between the forward and rearward positions by an electric motor driven pulley or worm gear arrangement of by a mechanical drive pulley arrangement such as shown in U.S. Pat. No. 3,770,078, issued to Keppel et al on Nov. 6, 1973. Another means of moving carriage fore and aft along the roof rail is disclosed in U.S. Pat. No. 3,770,294, issued to Hammer on Nov. 6, 1973 where a cable extends between the carriage and the door to pull the carriage forwardly as the door is opened.